//
// generic/datagram_protocol.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef ASIO_GENERIC_DATAGRAM_PROTOCOL_HPP
#define ASIO_GENERIC_DATAGRAM_PROTOCOL_HPP

#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

#include "asio/detail/config.hpp"

#include <typeinfo>
#include "asio/basic_datagram_socket.hpp"
#include "asio/detail/socket_types.hpp"
#include "asio/detail/throw_exception.hpp"
#include "asio/generic/basic_endpoint.hpp"

#include "asio/detail/push_options.hpp"

namespace asio {
    namespace generic {

/// Encapsulates the flags needed for a generic datagram-oriented socket.
/**
 * The asio::generic::datagram_protocol class contains flags necessary
 * for datagram-oriented sockets of any address family and protocol.
 *
 * @par Examples
 * Constructing using a native address family and socket protocol:
 * @code datagram_protocol p(AF_INET, IPPROTO_UDP); @endcode
 * Constructing from a specific protocol type:
 * @code datagram_protocol p(asio::ip::udp::v4()); @endcode
 *
 * @par Thread Safety
 * @e Distinct @e objects: Safe.@n
 * @e Shared @e objects: Safe.
 *
 * @par Concepts:
 * Protocol.
 */
        class datagram_protocol {
        public:
            /// Construct a protocol object for a specific address family and protocol.
            datagram_protocol(int address_family, int socket_protocol)
                    : family_(address_family),
                      protocol_(socket_protocol) {
            }

            /// Construct a generic protocol object from a specific protocol.
            /**
             * @throws @c bad_cast Thrown if the source protocol is not datagram-oriented.
             */
            template<typename Protocol>
            datagram_protocol(const Protocol &source_protocol)
                    : family_(source_protocol.family()),
                      protocol_(source_protocol.protocol()) {
                if (source_protocol.type() != type()) {
                    std::bad_cast ex;
                    asio::detail::throw_exception(ex);
                }
            }

            /// Obtain an identifier for the type of the protocol.
            int type() const

            ASIO_NOEXCEPT
            {
                return ASIO_OS_DEF(SOCK_DGRAM);
            }

            /// Obtain an identifier for the protocol.
            int protocol() const

            ASIO_NOEXCEPT
            {
                return protocol_;
            }

            /// Obtain an identifier for the protocol family.
            int family() const

            ASIO_NOEXCEPT
            {
                return family_;
            }

            /// Compare two protocols for equality.
            friend bool operator==(const datagram_protocol &p1,
                                   const datagram_protocol &p2) {
                return p1.family_ == p2.family_ && p1.protocol_ == p2.protocol_;
            }

            /// Compare two protocols for inequality.
            friend bool operator!=(const datagram_protocol &p1,
                                   const datagram_protocol &p2) {
                return !(p1 == p2);
            }

            /// The type of an endpoint.
            typedef basic_endpoint <datagram_protocol> endpoint;

            /// The generic socket type.
            typedef basic_datagram_socket <datagram_protocol> socket;

        private:
            int family_;
            int protocol_;
        };

    } // namespace generic
} // namespace asio

#include "asio/detail/pop_options.hpp"

#endif // ASIO_GENERIC_DATAGRAM_PROTOCOL_HPP
